It is basically known that the energy of a laser beam can be used in processing circuit boards and comparable types of electrical circuit substrates. The use of a UV laser with a continuously pumped, quality switched Nd.YAG laser for drilling microholes in a multilayer substrate is known from U.S. Pat. No. 5,593,606. Typical repetition rates of up to 5 kHz are used here.
A method of forming at least two wiring layers on piezoelectric isolated sublayers is known from EP 931 439 B1, whereby a laser, preferably an Nd-YAG, is used both for drilling blind holes and for structuring conductor tracks. When conductor tracks are formed either the metal layer itself can be structured by the laser by partial removal or its is also possible to partially remove an etch resist layer lying on the metal layer with the laser and then etch off the area of the metal layer revealed.
Basically it is also known that laser beams can be used to expose photo resist layers. It is proposed in EP 1 115 031 A2 for this purpose to use a titanium-sapphire laser with repetition rates of more than 80 MHz which generates a quasi-continuous UV laser beam.
Depending on the application different laser systems are accordingly used which require significant investment outlay if different processing methods are to be used one after the other in circuit board manufacturing.